Physiological sensor having a waist

ABSTRACT

An exemplary sensor includes a sensor pad having a first portion and a second portion separated by a waist portion. The waist portion is narrower than the first portion and the second portion. A light source that is disposed on the first portion is configured to generate near-infrared light and transmit the near-infrared light through part of a patient&#39;s body. A light detector that is disposed on the second portion is configured to detect near-infrared light that has traveled through the part of the patient&#39;s body. The near-infrared light detected indicates an amount of oxygen in the part of the patient&#39;s body through which the near-infrared light traveled.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Ser. No. 61/228,086 filed Jul.23, 2009, which is incorporated herein by reference in its entirety.

BACKGROUND

Near-infrared sensors are used in the medical industry to measure theamount of oxygen saturation in a patient's blood or tissue. Thesesensors work by detecting light after it has traveled through a portionof the patient's body. However, ambient or other light may interferewith the sensor, providing medical personnel with false readings thatmay lead to missed diagnoses and incorrect treatments. Existingsolutions to blocking ambient light results in sensors that are bulkyand expensive to manufacture. Moreover, these bulky sensors are not veryflexible and cannot always conform to the contours of a patient's body.Accordingly, a physiological sensor is needed that protects againstinterference from ambient and other forms of light but is flexibleenough to conform to the contours of the patient's body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary sensor having a sensor pad with a waistportion.

FIG. 2 illustrates an exemplary sensor having another sensor pad with awaist portion.

FIG. 3 illustrates an exemplary sensor having a liner disposed on thesensor pad.

FIG. 4 illustrates the exemplary sensor of FIG. 1 disposed on a patient.

DETAILED DESCRIPTION

An exemplary physiological sensor that blocks interfering light andprovides sufficient flexibility includes a sensor pad having a firstportion and a second portion separated by a waist portion. The waistportion is narrower than the first portion and the second portion. Alight source disposed on the first portion is configured to generatenear-infrared light and transmit the near-infrared light through part ofa patient's body. A light detector disposed on the second portion isconfigured to detect near-infrared light that has traveled through thepart of the patient's body. The near-infrared light detected indicatesan amount of oxygen in the part of the patient's body through which thenear-infrared light traveled.

FIG. 1 illustrates an exemplary sensor 100 that conforms to the contoursof a patient's body and is able to prevent interference from ambientlight. The sensor 100 may take many different forms and include multipleand/or alternate components and facilities. While an exemplary sensor100 is shown in FIG. 1, the exemplary components illustrated in thefigures are not intended to be limiting. Indeed, additional oralternative components and/or implementations may be used.

As illustrated in FIG. 1, the sensor 100 includes a sensor pad 105housing a light source 110 and a light detector 115. Of course, thesensor pad 105 may house any number of light sources 110 and lightdetectors 115. Indeed, one light source 110 and two light detectors 115are illustrated in FIG. 1. FIG. 2 illustrates a sensor 100 with twolight sources 110 and two light detectors 115. As illustrated in FIGS. 1and 2, the sensor 100 may further include an adhesive 120 disposed onthe sensor pad 105 and a connector 145.

The sensor pad 105 may be formed from any material configured to housethe light source 110 and light detector 115. For instance, the sensorpad 105 may be formed from two or more layers 125 of a flexible materialthat sandwich one or more circuit boards (not shown) with the lightsource 110, the light detector 115, or both. At least one of the layers125 may include a light blocking material. That is, one of the layers125 may be opaque to ambient and other types of light that may interferewith the light detector 115. When placed on a patient, one layer 125 isdisposed on the patient's skin while the other layer 125 is spaced fromthe patient's skin. In one exemplary approach, the layer 125 spaced fromthe patient's skin includes the light blocking material. Of course, bothlayers 125 may include the light blocking material and the layer 125disposed on the patient's skin may define openings in line with thelight source 110 and light detector 115. Further, one or both of thelayers 125 may include a flexible material so that the sensor 100 maybend to fit the contours of the patient's body.

The sensor pad 105 may define a first portion 130 that may house thelight source 110 and/or the light detector 115, a second portion 135that may house the light source 110 and/or the light detector 115, and awaist portion 140 that separates the first portion 130 and the secondportion 135. The first portion 130, the second portion 135, and thewaist portion 140 may be integrally formed with one another from thelayers 125 of the sensor pad 105. Additionally, the first portion 130,the second portion 135, the waist portion 140, or any combinationthereof, may include the light blocking material and/or the flexiblematerial. In one exemplary approach, only the second portion 135includes the light blocking material and only the waist portion 140includes the flexible material. However, in the interest of reducingmanufacturing complexity, each of the first portion 130, the secondportion 135, and the waist portion 140 may include both the lightblocking material and the flexible material.

The second portion 135 may have a larger surface area than the firstportion 130 and the waist portion 140. The larger surface area helps thesensor pad 105 block interfering light, such as ambient light. With thelarger surface area, it is less likely that the light detector 115 willreceive interfering light and provide false oximetry readings. Since thelight source 110 does not need protection against interfering light,manufacturing the sensor 100 so that the first portion 130 has a smallersurface area than the second portion 135 results in reduced materialcosts. Alternatively, however, the second portion 135 and the firstportion 130 may have the same surface area.

The waist portion 140 may be narrower than the first portion 130 and thesecond portion 135 to provide the sensor 100 with additional flexibilityto fit the contours of the patient. In one exemplary implementation, thefirst portion 130 and the second portion 135 may gradually taper to thewidth of the waist portion 140, thus providing a smooth transitionbetween the first portion 130, the waist portion 140, and the secondportion 135. Alternatively, one or both of the first portion 130 and thesecond portion 135 may transition to the waist portion 140 moreabruptly.

The light source 110 may include any device that is able to generatenear-infrared light. For instance, the light source 110 may include alight emitting diode (LED) or a laser diode. Of course, the light source110 may include additional or alternative devices. Further, the sensor100 may include any number of light sources 110. For example, asillustrated in FIG. 2, the sensor 100 includes two light sources 110within the first portion 130.

The light detector 115 may include any device configured to detectnear-infrared light. The light detector 115, therefore, may include aphotodiode. Any number of light detectors 115 may be disposed on thesensor pad 105. As illustrated in FIGS. 1 and 2, the sensor pad 105houses two light detectors 115.

The adhesive 120 is disposed on the layer 125 of the sensor pad 105 thatwill be disposed on the patient while the sensor 100 is in use. Theadhesive 120 may include any adhesive 120 that is able to hold thesensor pad 105 in place relative to the patient's body. For example, theadhesive 120 may include a pressure sensitive adhesive 120.

The connector 145 may extend from the sensor pad 105 and be used tocontrol the light source 110 and light detector 115. Moreover, theconnector 145 may transmit signals representing the light received bythe light detector 115 to a controller (not shown) for furtherprocessing.

FIG. 3 illustrates an exemplary sensor 100 having a liner 150 disposedon the adhesive 120. The liner 150 may, for example, prevent theadhesive 120 from adhering the sensor pad 105 to unintended objectsuntil the sensor 100 is ready to be placed on a patient. The liner 150may be formed from any material that adheres to the adhesive 120 butwill not significantly remove the adhesive 120 when the liner 150 isremoved. The liner 150 may be formed from one or more pieces. Forinstance, in the exemplary approach of FIG. 3, the liner 150 is formedfrom two pieces.

The liner 150 defines a slit 155 over the waist portion 140. The slit155 and flexibility of the waist portion 140 may allow a user of thesensor 100 to easily remove the liner 150. For instance, the user maybend the waist portion 140 as illustrated in FIG. 3 to expose two tabs160. The user may further pull each tab 160 to remove each piece of theliner 150 from the sensor 100. Removing the liner 150 exposes theadhesive 120. With the liner 150 removed, the user may adhere the sensor100 to the patient.

FIG. 4 illustrates the sensor 100 disposed on a patient. As illustrated,the near-infrared light 170 from the light source 110 is transmittedthrough blood or tissue and is received by the light detector 115. Thelight detector 115 generates a signal that indicates the oxygensaturation of the blood or tissue through which the light 170 traveled.The second portion 135 of the sensor pad 105 has a larger surface areathan the first portion 130. While some interfering light 175 such asambient light may travel through the tissue, the large surface area ofthe second portion 135 reduces the amount of interfering light 175 thatis received by the sensor 100. FIG. 4 further illustrates the waistportion 140 that is narrower than the first portion 130 and the secondportion 135. This gives the sensor 100 additional flexibility to fit thecontours of the patient's body.

With regard to the processes, systems, methods, heuristics, etc.described herein, it should be understood that, although the steps ofsuch processes, etc. have been described as occurring according to acertain ordered sequence, such processes could be practiced with thedescribed steps performed in an order other than the order describedherein. It further should be understood that certain steps could beperformed simultaneously, that other steps could be added, or thatcertain steps described herein could be omitted. In other words, thedescriptions of processes herein are provided for the purpose ofillustrating certain embodiments, and should in no way be construed soas to limit the claimed invention.

Accordingly, it is to be understood that the above description isintended to be illustrative and not restrictive. Many embodiments andapplications other than the examples provided would be apparent uponreading the above description. The scope of the invention should bedetermined, not with reference to the above description, but shouldinstead be determined with reference to the appended claims, along withthe full scope of equivalents to which such claims are entitled. It isanticipated and intended that future developments will occur in thetechnologies discussed herein, and that the disclosed systems andmethods will be incorporated into such future embodiments. In sum, itshould be understood that the invention is capable of modification andvariation.

All terms used in the claims are intended to be given their broadestreasonable constructions and their ordinary meanings as understood bythose knowledgeable in the technologies described herein unless anexplicit indication to the contrary in made herein. In particular, useof the singular articles such as “a,” “the,” “said,” etc. should be readto recite one or more of the indicated elements unless a claim recitesan explicit limitation to the contrary.

1. A sensor comprising: a sensor pad having a first portion and a secondportion separated by a waist portion, wherein the waist portion isnarrower than the first portion and the second portion; a light sourceconfigured to generate near-infrared light and transmit thenear-infrared light through part of a patient's body; and a lightdetector configured to detect near-infrared light that has traveledthrough the part of the patient's body, wherein the near-infrared lightdetected indicates an amount of oxygen in the part of the patient's bodythrough which the near-infrared light traveled.
 2. A sensor as set forthin claim 1, wherein the second portion is configured to substantiallyprevent the light detector from receiving interfering light.
 3. A sensoras set forth in claim 1, wherein the second portion includes a lightblocking material.
 4. A sensor as set forth in claim 1, wherein at leastone of the first portion and the waist portion includes a light blockingmaterial.
 5. A sensor as set forth in claim 1, further comprising anadhesive disposed on the sensor pad.
 6. A sensor as set forth in claim5, further comprising a liner disposed on the adhesive.
 7. A sensor asset forth in claim 6, wherein the liner defines a slit.
 8. A sensor asset forth in claim 7, wherein the slit is located over the waistportion.
 9. A sensor as set forth in claim 1, wherein the waist portionincludes a flexible material.
 10. A sensor as set forth in claim 1,wherein at least one of the first portion and the second portionincludes a flexible material.
 11. A sensor pad comprising: a firstportion configured to house a light source that generates near-infraredlight and transmits the near-infrared light through a part of apatient's body; a second portion configured to house a light detectorthat detects near-infrared light after the near-infrared light hastraveled through a part of the patient's body, wherein the lightreceived indicates oxygen saturation of the part of the patient's bodythrough which the light traveled; and a waist portion disposed betweenthe first portion and the second portion, wherein the waist portion isnarrower than the first portion and the second portion.
 12. A sensor padas set forth in claim 11, wherein the second portion includes a lightblocking material that substantially prevents the light detector fromreceiving interfering light.
 13. A sensor pad as set forth in claim 11,wherein at least one of the first portion and the waist portion includea light blocking material.
 14. A sensor pad as set forth in claim 11,wherein the waist portion includes a flexible material.
 15. A sensor padas set forth in claim 11, wherein at least one of the first portion andthe second portion includes a flexible material.
 16. A sensor pad as setforth in claim 11, further comprising an adhesive disposed on the firstportion and the second portion.
 17. A sensor pad as set forth in claim16, further comprising a liner disposed on the adhesive.
 18. A sensorpad as set forth in claim 17, wherein the liner defines a slit locatedover the waist portion.
 19. A sensor comprising: a sensor pad having afirst portion and a second portion separated by a waist portion, whereinthe waist portion is narrower than the first portion and the secondportion, the second portion including a light blocking material and thewaist portion including a flexible material; a light source disposed onthe first portion and configured to generate near-infrared light andtransmit the near-infrared light through a part of a patient's body; alight detector disposed on the second portion and configured to detectnear-infrared light that has traveled through part of the patient's bodyto identify an amount of oxygen in the part of the patient's bodythrough which the near-infrared light traveled, and wherein the secondportion substantially prevents the light detector from receivinginterfering light; an adhesive disposed on the sensor pad; and a linerdisposed on the adhesive and defining a slit located near or over thewaist portion.
 20. A sensor as set forth in claim 19, wherein at leastone of the first portion and the second portion includes a flexiblematerial.
 21. A sensor as set forth in claim 19, wherein at least one ofthe first portion and the waist portion includes a light blockingmaterial.